Tube cutter

ABSTRACT

A plurality of wedge-shaped cutting members having spaced arcuate cutting edges are urged radially inwardly by fluid pressure to contract about and sever a mandrel-held tube in two longitudinally spaced planes. Each cutting member has spaced side cutting edges adapted to engage the spaced side cutting edges of an adjacent cutting member, thereby to remove flash resulting from the severing operation. The fluid pressure is exerted through a resilient sheathing simultaneously about the entire array of cutting members. Leaf springs urge the entire array radially outwardly to expand the array when fluid pressure is removed from the array of cutting members.

1451 Sept. 4, 1973 TUBE CUTTER [75] Inventor: Francis Joseph Fuchs, Jr.,Princeton Junction, NJ.

[73] Assignee: Western Electric Company,

Incorporated, New York, NY.

22 Filed: Dec. 13,1971

211 App]. No.: 207,333

83/688 51 Int. (:1 ..B26d 3/16 [58] Field of Search 83/193, 192, 194,

[56] References Cited UNITED STATES PATENTS 3,478,388 11/1969 Turner83/54 X FOREIGN PATENTS OR APPLICATIONS 784,289 10/1957 Great Britain83/193 Primary ExaminerFrank T. Yost Attorney-Jack Schuman [57] ABSTRACTA plurality of wedge-shaped cutting members having spaced arcuatecutting edges are urged radially inwardly by fluid pressure to contractabout and sever a mandrel-held tube in two longitudinally spaced planes.Each cutting member has spaced side cutting edges adapted to engage thespaced side cutting edges of an adjacent cutting member, thereby toremove flash resulting from the severing operation. The fluid pressureis exerted through a resilient sheathing simultaneously about the entirearray of cutting members. Leaf springs urge the entire array radiallyoutwardly to expand the array when fluid pressure is removed from thearray of cutting members.

8 Claims, 4 Drawing Figures :1 \v //4 llllll x e 7 4/5 M 1 PatentedSept. 4, 1973 2 Sheets-Sheet l INVENTOR. BYFRANCIS J. FUCHS JR.

ATTORNEY Patented sept. 4, 1973 3,756,108

2 Sheets-Sheet 2 INVENTOR. FRANCIS J. FUCHS JR. BY 6 ATTORNEY TUBECUTTER 1. Field of the Invention This invention relates broadly toapparatus for cutting tubes. More specifically, this invention relatesto apparatus for transversely severing a tube about its circumferencewithout leaving a flash around the line of severance.

2. Description of the Prior Art In one form of prior art apparatus, atube to be cut is positioned on a pair of aligned mandrels and receivedwithin a pair of aligned dies positioned concentrically about themandrels. The mandrels and dies are moved transversely of each other tocause transverse shearing of the tube.

In another form of prior art apparatus, the cutting tool comprises acutting wheel which is advanced around the outer surface of a tube to becut, each pass of the cutting tool around the tube being accompanied bya radially inward adjustment of the cutting wheel to cause the cut tobecome increasingly deeper with each pass until the tube is cut.

The above mentioned prior art apparatus and the methods practicedthereby for cutting tubes, as well as the other apparatus and methodswhich they typify, are both expensive and somewhat less than entirelysatisfactory in their operation. They have been expensive to the extentthat their mode of operation is protracted, and have been somewhat lessthan satisfactory to the extent that they create and leave flashes onthe tubes along the line of severance, which flashes for mostapplications must be removed by a separate manufacturing operationthereby generating additional expense.

Representative prior art appears in the following patents:

US. Pat. No. 3,374,697 (1968) to Robinson U.S. Pat. No. 3,279,289 (1966)to Wendricks U.S. Pat. No. 3,273,433 (1966) to Borzym U.S. Pat. No.1,981,059 (1934) to Matthews et al.

SUMMARY OF THE INVENTION One of the objects of this invention is toprovide improved apparatus for cutting tubes.

Another of the objects of this invention is to provide improvedapparatus for transversely severing a tube about its circumferencewithout leaving a flash around the line of severance.

A further object of this invention is to provide improved apparatus forrapidly and smoothly severing a tube about its circumference.

Still other and further objects of this invention will become apparentduring the course of the following description and by reference to theaccompanying drawings and the appended claims.

Briefly, I have discovered that the foregoing objects may be obtained byproviding a plurality of wedgeshaped, radially convergent cuttingmembers having spaced arcuate front cutting edges for engaging andsevering the tube, and also having spaced side cutting edges forengaging and severing any flashing produced by the cutting action of thefront cutting surfaces.

BRIEF DESCRIPTION OF THE DRAWINGS Referring now to the drawings in whichlike numerals represent like parts in the several views:

FIG. 1 represents a medial longitudinal section of the tube cutter ofthe present invention;

FIG. 2 represents a transverse half section of the tube cutter takenalong the line A-A of FIG. 1, with the cutting members in open position;

FIG. 3 represents a transverse half section of the tube cutter takenalong the line A-A of FIG. 1, with the cutting members in closedposition; and

FIG. 4 represents a view in perspective of one of the cutting members.

DESCRIPTION OF THE PREFERRED EMBODIMENT Tube cutter l for severing tube2, preferably internally supported on mandrel 3, is seen as comprisinghousing 4 having female threaded portions 5 and 6 above and below,respectively, an internal land portion 7, and threaded members 8 and 9screwed into threaded portions 5 and 6; respectively. Members 8 and 9are provided with aligned central apertures 10 and 11, respectively,which apertures 10 and 11 are of diameter such as to slidably receivetube 2.

The facing sides of members 8 and 9 are recessed, as shown in FIG. 1,thereby to define, in cooperation with land portion 7 of housing 4, anannular chamber 12, and further to define therebetween, a transverselyarranged circular chamber 13 open toward the external surface of tube 2.1 I

A plurality of radially arranged wedge-shaped cutting members 14 arepositioned in tube cutter 1, between members 8 and 9. Each cuttingmember 14 comprises a main body portion 15 slidably mounted in circularchamber 13, a rear enlarged portion 16 slidably mounted within chamber12, and spaced forward arcuate cutting edges 17 projecting from the topand bottom surfaces of main body portion 15. Along the top and bottomsurfaces of main body portion 15 are provided spaced side cutting edges18 proportioned to engage the side cutting edges 18 of the adjacentcutting member 14 when the cutting members 14 are fully extendedradially inwardly.

Mounted within annular chamber 12 is a resilient member 19 whichcompletely surrounds all of the cutting members 14 and which defines,with land portion 7 of housing 4, an expandable chamber 20 communicatingthrough openings 21 formed through housing 4, with a source (not shown)of pressurized fluid. Seals 22 are provided as shown.

Positioned within annular chamber 12 are circular leaf springs 23 biasedto bear outwardly against the upper and lower portions of enlargedportions 16 of all cutting members 14 and to urge all of said cuttingmembers 14 radially outwardly.

The operation of the present invention will now be described.

Tube 2, preferably supported on mandrel 3, is inserted into centralapertures 10 and 11, and that portion of tube 2 at which the cuts are tobe made is aligned with arcuate cutting edges 17. So far, cuttingmembers 14 have been urged radially outwardly to an expanded state bymeans of leaf springs 23 bearing against rear enlarged portions 16 ofthe cutting members l4.

Fluid pressure is now introduced through openings 21 into expandablechamber 20 and therein acting on resilient member 19 which, in effect,constitutes the moving wall of the said expandable chamber 20, whereuponresilient member l9simultaneously forces all of said cutting members 14radially inwardly thereby to force arcuate cutting edges 17 through thewall of tube 2 against mandrel 3, the said arcuate cutting edges 17meeting and forming the perimeters of two longitudinally spaced closedcircles in this contracted state whereby to sever the tube 2 completelyaround its perimeter in two longitudinally spaced planes.Simultaneously, side cutting edges 18 of each cutting member 14 engage,in this contracted condition of cutting members 14, the side cuttingedges 18 of the adjacent cutting member 14, whereby a small length oftube 2 is severed between the spaced arcuate cutting edges 17 and maysubsequently, be discarded, and any flash of material produced duringthis cutting operation and projecting into the space between the spacedside cutting elements is excised together with the hereinabove mentionedsmall length of tube 2. In this manner, clean flashless cuts are made intube 2 and the severed portions of tube 2 may be withdrawn.

Upon release of pressure from expandable chamber 20, leaf springs 23,bearing against the enlarged rear portions 16 of cutting members 14,urge the said cutting members 14 radially outwardly to an expandedstate.

What i claim is:

1. Apparatus for flashlessly cutting transversely through the wall of atubular member thereby to sever the tubular member, said apparatuscomprising:

a. a circular array of radially reciprocable cutting members, saidcircular array having a central aperture adapted to receive said tubularmembers;

b. each cutting member comprising:

i. first cutting means on the forward end thereof adjacent said centralaperture and adapted to face said tubular member;

ii. second cutting means mounted to a side of said cutting member andadapted to engage second cutting means on the side of the adjacentcutting member when said cutting members are radially inwardly advancedinto the said centralaperture and through the wall of said tubularmember;

0. operating means associated with said cutting members tosimultaneously advance all of said cutting members radially inwardly ofsaid circular array thereof into the said central aperture and throughthe wall of said tubular member thereby to cleanly transversely seversaid tubular member and simultaneously therewith sever flash producedthereby; and

d. said operating means comprises:

i, a circular chamber surrounding the circular array of cutting member;

ii. a movable wall constituting one wall of said circular chamber andcontacting those ends of said cuttingmembers remote from the centralaperture;

iii. conduit means communicating with said circular chamber and adaptedto introduce pressurized fluid into said circular chamber on that sideof said movable wall opposite said cutting members.

2. Apparatus for flashlessly cutting transversely through the wall of atubular member thereby to sever the tubular member, said apparatuscomprising:

a. a circular array of radially reciprocable cutting members, saidcircular array having a central aperture adapted to receive said tubularmember;

b. each cutting member comprising:

i. first cutting means on the forward end thereof adjacent said centralaperture and adapted to face said tubular member;

ii. second cutting means mounted to a side of said cutting member andadapted to engage second cutting means on the side of the adjacentcutting member when said cutting members are radially inwardly advancedinto the said central aperture and through the wall of said tubularmember;

c. operating means associated with said cutting members tosimultaneously advance all of said cutting members radially inwardly ofsaid circular array thereof into the said central aperture and throughthe wall of said tubular member thereby to cleanly transversely seversaid tubular member and simultaneously therewith sever flash producedthereby; each of said cutting members being formed with an enlarged rearend;

e. said operating means comprising:

i. a circular chamber surrounding the circular array of cutting members;

ii. a movable circular wall constituting the inner wall of said circularchamber and contacting the enlarged rear ends of said cutting members;

iii, conduit means communicating with said circular chamber and adaptedto introduce pressurized fluid into said circular chamber on that sideof said movable wall opposite said cutting members.

3. Apparatus as in claim 2, further comprising:

f. retracting means engaging said enlarged rear ends of said cuttingmembers and adapted to simultaneously withdraw all of said cuttingmembers radially outwardly from said central aperture.

4. Apparatus as in claim 3, wherein:

g. said retracting means comprises a spring member located inwardly ofsaid enlarged rear ends of said cutting members and urging said cuttingmembers radially outwardly.

5. Apparatus for flashlessly cutting transversely through the wall of atubular member thereby to sever the tubular member, said apparatuscomprising:

a. a circular array of radially reciprocable cutting members, saidcircular array having a central aperture adapted to receive said tubularmember;

b. each cutting member comprising:

i. first cutting means on the forward end thereof adjacent said centralaperture and adapted to face said tubular member;

ii. second cutting means mounted to a side of said cutting member andadapted to engage second cutting means on the side of the adjacentcutting member when said cutting members are radially inwardly advancedinto the said central aperture and through the wall of said tubularmember;

0. operating means associated with said cutting members tosimultaneously advance all of said cutting members radially inwardly ofsaid circular array thereof into the said central aperture and throughthe wall of said tubular member thereby to cleanly transversely seversaid'tubular member and simultaneously therewith sever flash producedthereby;

d. each of said cutting members having a first surface and a secondsurface longitudinally spaced therefrom;

e. the first cutting means on each cutting member comprising:

i. a first forward cutting edge adjacent said first surface;

ii. a second forward cutting edge adjacent said second surface andlongitudinally spaced from said first forward cutting edge;

f. the second cutting means on each cutting member comprising:

i. a first side cutting edge adjacent said first surface behind saidfirst forward cutting edge;

ii. a second side cutting edge adjacent said second surface andlongitudinally spaced from said first side cutting edge and behind saidsecond forward cutting edge.

6. Apparatus as in claim 5, wherein:

g. said first forward cutting edge and said first side cutting edge forma continuous cutting edge extending along the forward end and the sideof said cutting member adjacent said first surface,

h. said second forward cutting edge and said second side cutting edgeform a continuous cutting edge extending along the forward end and theside of said cutting member adjacent the second surface.

7. Apparatus as in claim 5, wherein:

g. the second cutting means on each cutting member further comprises:

iii. a third side cutting edge adjacent said first surface behind saidfirst forward cutting edge and opposite said first side cutting edge,

iv. a fourth side cutting edge adjacent said second surface behind saidsecond forward cutting edge and opposite said second side cutting edgeand longitudinally spaced from said third side cutting edge.

8. Apparatus as in claim 7, wherein:

h. said first forward cutting edge, said first side cutting edge andsaid third side cutting edge form a continuous cutting edge extendingalong two opposite sides and the forward end of said cutting memberadjacent said first surface;

i. said second forward cutting edge, said second side cutting edge andsaid fourth side cutting edge form a continuous cutting edge extendingalong two opposite sides and the forward end of said cutting memberadjacent said second surface.

1. Apparatus for flashlessly cutting transversely through the wall of atubular member thereby to sever the tubular member, said apparatuscomprising: a. a circular array of radially reciprocable cuttingmembers, said circular array having a central aperture adapted toreceive said tubular members; b. each cutting member comprising: i.first cutting means on the forward end thereof adjacent said centralaperture and adapted to face said tubular member; ii. second cuttingmeans mounted to a side of said cutting member and adapted to engagesecond cutting means on the side of the adjacent cutting member whensaid cutting members are radially inwardly advanced into the saidcentral aperture and through the wall of said tubular member; c.operating means associated with said cutting members to simultaneouslyadvance all of said cutting members radially inwardly of said circulararray thereof into the said central aperture and through the wall ofsaid tubular member thereby to cleanly transversely sever said tubularmember and simultaneously therewith sever flash produced thereby; and d.said operating means comprises: i. a circular chamber surrounding thecircular array of cutting member; ii. a movable wall constituting onewall of said circular chamber and contacting those ends of said cuttingmembers remote from the central aperture; iii. conduit meanscommunicating with said circular chamber and adapted to introducepressurized fluid into said circular chamber on that side of saidmovable wall opposite said cutting members.
 2. Apparatus for flashlesslycutting transversely through the wall of a tubular member thereby tosever the tubular member, said apparatus comprising: a. a circular arrayof radially reciprocable cutting members, said circular array having acentral aperture adapted to receive said tubular member; b. each cuttingmember comprising: i. first cutting means on the forward end thereofadjacent said central aperture and adapted to face said tubular member;ii. second cutting means mounted to a side of said cutting member andadapted to engage second cutting means on the side of the adjacentcutting member when said cutting members are radially inwardly advancedinto the said central aperture and through the wall of said tubularmember; c. operating means associated with said cutting members tosimultaneously advance all of said cutting members radially inwardly ofsaid circular array thereof into the said central aperture and throughthe wall of said tubular member thereby to cleanly transversely seversaid tubular member and simultaneously therewith sever flash producedthereby; d. each of said cutting members being formed with an enlargedrear end; e. said operating means comprising: i. a circular chambersurrounding the circular array of cutting members; ii. a movablecircular wall constituting the inner wall of said circular chamber andcontacting the enlarged rear ends of said cutting members; iii. conduitmeans communicAting with said circular chamber and adapted to introducepressurized fluid into said circular chamber on that side of saidmovable wall opposite said cutting members.
 3. Apparatus as in claim 2,further comprising: f. retracting means engaging said enlarged rear endsof said cutting members and adapted to simultaneously withdraw all ofsaid cutting members radially outwardly from said central aperture. 4.Apparatus as in claim 3, wherein: g. said retracting means comprises aspring member located inwardly of said enlarged rear ends of saidcutting members and urging said cutting members radially outwardly. 5.Apparatus for flashlessly cutting transversely through the wall of atubular member thereby to sever the tubular member, said apparatuscomprising: a. a circular array of radially reciprocable cuttingmembers, said circular array having a central aperture adapted toreceive said tubular member; b. each cutting member comprising: i. firstcutting means on the forward end thereof adjacent said central apertureand adapted to face said tubular member; ii. second cutting meansmounted to a side of said cutting member and adapted to engage secondcutting means on the side of the adjacent cutting member when saidcutting members are radially inwardly advanced into the said centralaperture and through the wall of said tubular member; c. operating meansassociated with said cutting members to simultaneously advance all ofsaid cutting members radially inwardly of said circular array thereofinto the said central aperture and through the wall of said tubularmember thereby to cleanly transversely sever said tubular member andsimultaneously therewith sever flash produced thereby; d. each of saidcutting members having a first surface and a second surfacelongitudinally spaced therefrom; e. the first cutting means on eachcutting member comprising: i. a first forward cutting edge adjacent saidfirst surface; ii. a second forward cutting edge adjacent said secondsurface and longitudinally spaced from said first forward cutting edge;f. the second cutting means on each cutting member comprising: i. afirst side cutting edge adjacent said first surface behind said firstforward cutting edge; ii. a second side cutting edge adjacent saidsecond surface and longitudinally spaced from said first side cuttingedge and behind said second forward cutting edge.
 6. Apparatus as inclaim 5, wherein: g. said first forward cutting edge and said first sidecutting edge form a continuous cutting edge extending along the forwardend and the side of said cutting member adjacent said first surface, h.said second forward cutting edge and said second side cutting edge forma continuous cutting edge extending along the forward end and the sideof said cutting member adjacent the second surface.
 7. Apparatus as inclaim 5, wherein: g. the second cutting means on each cutting memberfurther comprises: iii. a third side cutting edge adjacent said firstsurface behind said first forward cutting edge and opposite said firstside cutting edge, iv. a fourth side cutting edge adjacent said secondsurface behind said second forward cutting edge and opposite said secondside cutting edge and longitudinally spaced from said third side cuttingedge.
 8. Apparatus as in claim 7, wherein: h. said first forward cuttingedge, said first side cutting edge and said third side cutting edge forma continuous cutting edge extending along two opposite sides and theforward end of said cutting member adjacent said first surface; i. saidsecond forward cutting edge, said second side cutting edge and saidfourth side cutting edge form a continuous cutting edge extending alongtwo opposite sides and the forward end of said cutting member adjacentsaid second surface.